I've got a hagstrom viking which sounds great and the pickups are fine, but when i try to clean it up with the volume or use the tone controls it just turns into a muddy mess.

Can you guys suggest some good replacements or modifications? i've got some experience with a soldering iron and i've changed out PUPs before.
I mostly play blues, classic rock and hard rock and use an 18watt clone.

Look up 50's wiring. It's the best modification for volume/tone pots I've ever heard. You can actually use them together and get great results.
Cusp of Magic
i'll give that a go, but i'm also wanting some replacement pots. the ones in it at the moment are pretty dicky. any recommendations?
I agree the Viking is a great guitar (jazz tones through to howling blues leads) but also find the vol pots and tone pots frustrating) As soon as you turn down the vol a notch or two you lose all the upper end. I overcame this on my strat by soldering a treble bleed mod (cap and resistor )across the pot. However with this setup with the pickup selector on both pickups treble bleeds on each vol pot would not work. One possibility is a seperate master vol pot with treble bleed but I'm reluctant to add another pot and it still wouldnt help blending pickups with the individual pots. .The tone pots also seem to have all the change in the first few notches . I hope someone here has come up with a better system.